Heat the broth in a small saucepan, keep at a low simmer. In a large saucepan heat the oil and butter on medium heat. Add onion to the butter and oil and stir until translucent. Add the rice and stir constantly to keep from burning, cook for 5 minutes. Add the wine, stir and reduce the wine by half. With heat at medium-low add 1 cup of warm broth and lemon zest, stir briefly and allow to reduce. Keep adding broth one cup at a time, stirring occasionally allowing each cup of broth to reduce before adding the next cup until the rice is al dente, about 20 ? 30 minutes (to prep ahead of time stop adding broth after about 15 minutes, chill broth and rice until ready to resume and finish adding re-warmed broth 1 cup at a time, until al dente). Stir in the peas and shrimp and add another 1/2 cup of broth, cook for 2 more minutes. Stir in parsley, Parmesan and lemon juice. Season with salt and pepper.